This invention relates generally to turbine engines and, more particularly, to a valve assembly for turbine engines.
At least some known aircraft turbine engines include a fan, a compressor, a combustor, a high pressure turbine, a low pressure turbine, and an augmentor or “afterburner”. Airflow entering the fan is compressed. Airflow exiting the fan is split such that a portion is directed into the compressor and the remaining portion, referred to as fan bypass flow, is directed into a bypass passage where it bypasses the compressor, the combustor, the high pressure turbine, and the low pressure turbine. Airflow entering the compressor is compressed and is discharged towards the combustor wherein it is mixed with fuel and ignited, producing hot combustion gases used to drive both the high pressure and the low pressure turbines. Moreover, at least some known turbine engines combine a portion of the fan bypass flow with the airflow exiting the low pressure turbine.
To regulate the amount of bypass air entering the augmentor, at least some turbine engines include a valve assembly. More specifically, in some known turbine engines, the flow of the fan bypass air is regulated based on specific exhaust liner pressure ratio requirements demanded for the type of flight mode of the aircraft. At least some known valve assemblies include a plurality of blocker doors that are independently adjusted to maintain exhaust liner pressure ratio requirements. As such, each blocker door includes a separate kinematic system, which may each include, for example, a plurality of crank-arm shafts and actuators. Accordingly, such valve assemblies are generally complex designs which add additional cost and weight to the aircraft.